Development and validation of the Japanese version of the Decisional Conflict Scale to investigate the value of pharmacists’ information: a before and after study

BackgroundThe information provided in patient-centered care and shared decision-making influences patients’ concerns and adherence to treatment. In the decision-making process, patients experience decisional conflict. The Decisional Conflict Scale (DCS) is a 16-item, self-administered questionnaire consisting of 5 subscales developed to assess patients’ decisional conflict. This study aimed to develop the Japanese version of the DCS and to clarify the influence of the information provided by pharmacists’ on decisional conflict among patients with cancer.MethodsWe developed the Japanese version of the DCS by using the forward-backward translation method. One hundred patients who were recommended a new chemotherapy regimen were recruited. The psychometric properties of the Japanese DCS, including internal consistency, convergent validity, discriminant validity, and construct validity, were examined. We assessed the decisional conflict of patients before and after the pharmacists’ provision of information.ResultsNinety-four patients, predominately female, with an average age of 58.1 years were sampled. The scores on the 5 subscales of the DCS showed high internal consistency (Cronbach’s alpha = 0.84–0.96). Multi-trait scaling analysis and cluster analysis showed strong validity. The mean total DCS score decreased significantly from 40.2 to 31.7 after patients received information from the pharmacists (p < 0.001, paired t-test). Scores on all 5 subscales, namely, uncertainty, informed, values clarity, support, and effective decision, also significantly improved (p < 0.001 for all categories, paired t-test).ConclusionsThe psychometric properties of the Japanese version of the DCS are considered appropriate for it to be administered to patients with cancer. Pharmacists’ provision of information was able to decrease decisional conflict among patients with cancer who were recommended a new chemotherapy regimen.

[1]  Sally Thorne,et al.  Communicating shared decision-making: cancer patient perspectives. , 2013, Patient education and counseling.

[2]  Adrian G Barnett,et al.  Regression to the mean: what it is and how to deal with it. , 2004, International journal of epidemiology.

[3]  B T Slingsby,et al.  Decision-making models in Japanese psychiatry: transitions from passive to active patterns. , 2004, Social science & medicine.

[4]  Jane C Weeks,et al.  Cancer patients' roles in treatment decisions: do characteristics of the decision influence roles? , 2010, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[5]  Dawn Stacey,et al.  Decision Making in Oncology: A Review of Patient Decision Aids to Support Patient Participation , 2008, CA: a cancer journal for clinicians.

[6]  R. Keeney.  Decision analysis: an overview. , 1982, Operations research.

[7]  Rob Horne,et al.  Patients' perceptions of information received about medication prescribed for bipolar disorder: implications for informed choice. , 2007, Journal of affective disorders.

[8]  Ralph L. Keeney,et al.  Feature Article - Decision Analysis: An Overview , 1982, Oper. Res..

[9]  S H Heisterkamp,et al.  Palliative chemotherapy or watchful waiting? A vignettes study among oncologists. , 2002, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[10]  Geoffrey Mitchell,et al.  Information giving and decision-making in patients with advanced cancer: a systematic review. , 2005, Social science & medicine.

[11]  R Jenkins,et al.  The Satisfaction with Information about Medicines Scale (SIMS): a new measurement tool for audit and research , 2001, Quality in health care : QHC.

[12]  Murielle Mauer,et al.  Baseline quality of life as a prognostic indicator of survival: a meta-analysis of individual patient data from EORTC clinical trials. , 2009, The Lancet. Oncology.

[13]  David Khayat,et al.  Changing patient perceptions of the side effects of cancer chemotherapy , 2002, Cancer.

[14]  J. Bengel,et al.  Information and decision making: patients' needs and experiences in the course of breast cancer treatment. , 2008, Patient education and counseling.

[15]  Takamaru Ashikaga,et al.  Discrepancy between preference and actual adjuvant therapy for breast cancer. , 2010, Clinical breast cancer.

[16]  J P Kassirer,et al.  Incorporating patients' preferences into medical decisions. , 1994, The New England journal of medicine.

[17]  M. Jefford,et al.  Informing and involving cancer patients in their own care. , 2002, The Lancet. Oncology.

[18]  Peter Tugwell,et al.  A survey of the decision‐making needs of Canadians faced with complex health decisions , 2003, Health expectations : an international journal of public participation in health care and health policy.

[19]  H Sakai,et al.  A cross-validation of the European Organization for Research and Treatment of Cancer QLQ-C30 (EORTC QLQ-C30) for Japanese with lung cancer. , 1998, European journal of cancer.

[20]  C. Bombardier,et al.  Guidelines for the process of cross-cultural adaptation of self-report measures. , 2000, Spine.

[21]  H. Welch,et al.  Preferences for chemotherapy in patients with advanced non-small cell lung cancer: descriptive study based on scripted interviews , 1998, BMJ.

[22]  D. Rothenbacher,et al.  Treatment decisions in palliative cancer care: patients' preferences for involvement and doctors' knowledge about it. , 1997, European journal of cancer.

[23]  Ulrich Jaehde,et al.  From oncology pharmacy to pharmaceutical care: new contributions to multidisciplinary cancer care , 2004, Supportive Care in Cancer.

[24]  P. Craft,et al.  Knowledge of treatment intent among patients with advanced cancer: a longitudinal study. , 2005, European journal of cancer care.

[25]  R. Emsley,et al.  Diabetic Patients’ Medication Underuse, Illness Outcomes, and Beliefs About Antihyperglycemic and Antihypertensive Treatments , 2009, Diabetes Care.

[26]  Tsuguya Fukui,et al.  Patients' preferences for involvement in treatment decision making in Japan , 2004, BMC family practice.

[27]  K C Carriere,et al.  Information needs and decisional preferences in women with breast cancer. , 1997, JAMA.

[28]  M. Mills,et al.  The importance of information giving for patients newly diagnosed with cancer: a review of the literature. , 1999, Journal of clinical nursing.

[29]  I. Kai,et al.  Japanese cancer patient participation in and satisfaction with treatment-related decision-making: A qualitative study , 2008, BMC public health.

[30]  N Horikawa,et al.  Changes in disclosure of information to cancer patients in a general hospital in Japan. , 2000, General hospital psychiatry.

[31]  A. O'Connor.  Validation of a Decisional Conflict Scale , 1995, Medical decision making : an international journal of the Society for Medical Decision Making.

[32]  Yon-Dschun Ko,et al.  Task allocation in cancer medication management - integrating the pharmacist. , 2011, Patient education and counseling.

[33]  I. Varekamp,et al.  The decisional conflict scale: further validation in two samples of Dutch oncology patients. , 2001, Patient education and counseling.